Stabilizer



Feb. 7, 1967 w. R. GARRETT 3,302,983

STABILIZER Filed Jan. 14, 1964 5 Sheets-Sheet 1 3 I W ///0/7? Gar/eff f 3 I I YNVENTOR BY fi m ATTORA/[V W. R. GARRETT STABILIZER 5 Sheets-Sheet 2 W////0/77 A. Gar/eff INVENTOR.

Feb. 7, 1967 Filed Jan. 14, 19 4 1967 w. R. GARRETT STABILIZER 5 Shets-Sheet 5) Filed Jan. 14, 1964 ATTO/P/VEV United States Patent 3,302,983 STABILIZER William R. Garrett, Midland, Tex., assignor to Drilco Oil Tools, Inc, Midland, Tex., a corporation of Texas Filed Jan. 14, 1964, Ser. No. 337,631 4 Claims. (Cl. 308-4) This invention pertains to stabilizers used in the rotary system of earth boring to maintain the drill string (partic ularly the part near the drill bit) concentric with the hole being bored. The invention is particularly adapted for use in drilling large holes, e.g. over 30 inches in diameter, for which ordinary stabilizers used in smaller size holes are not suitable.

Stabilizers generally are of two types, n0n-rotary and rotary, the non-rotary type including an annular externally ribbed member remaining azimuthally stationary in the hole while the drill string rotates inside, the rotary type including an externally ribbed body that rotates with the string. The rotary type is not useful in a large hole because the ribs rotating with the drill string have a high peripheral speed tending to damage the hole or the stabilizer or to get stuck in the hole. The non-rotary type stabilizer is not practical in large sizes because of the large bearing surfaces involved and because of the constructional difficulties related to bracing of the annular member to provide enough stiifness to effect the desired stabilizer function.

According to the present invention the deficiencies of the conventional fixed and rotary stabilizers when large size is a requirement are overcome by a novel construction including an annular member having a plurality of rolling wall contacting means at its outer periphery. The annular member itself is of an open work construction providing maximum stilfness with minimum weight, the annular member including vertically spaced horizontal plates with azimuthally spaced radial plates therebetween. Each rolling wall-contacting means is preferably in the form of a steel-reinforced, rubber roller individually rotatably mounted on an axle that is connected to the annular member. The roller of the rolling wall-contacting means is releasably mounted so that it can be replaced when worn out. The rolling wall-contacting means as a whole is mounted in a support which is releasably connected to the annular member, so that if desired an extension can be inserted between the support and the annular member to position the wall-contacting means radially farther from the axis of the annular member to adapt the stabilizer for use in a larger size hole. Different extension members may be employed for different hole sizes.

For a detailed description of preferred embodiments of the invention reference will now be made to the accompanying drawings wherein FIGURE 1 is a fragmentary view, partly in elevation and partly in section, showing a stabilizer embodying the invention, the section plane being indicated at 1-1 in FIGURE 2;

FIGURE 2 is a plan view of the stabilizer shown in FIGURE 1;

FIGURE 3 is a plan view of a fragment of the stabilizer shown in FIGURE 2, with an extension member added;

FIGURE 4 is a vertical section taken at plane 44 of FIGURE 3;

FIGURE 5 is an enlarged elevational view, partly in section, showing one of the rolling, wall-contacting means ice and its support, used in the stabilizer of FIGURES 1-4 (and 78);

FIGURE 6 is a horizontal section through the rolling, wall-contacting means of FIGURE 5, taken at the plane indicated at 44 in FIGURE 5.

FIGURE 7 is a fragmentary view partly in elevation and partly in vertical section taken in the plane indicated at 7-7 on FIGURE 8, showing a modified form of stabilizer; and

FIGURE 8 is a plan view of the stabilizer shown in FIGURE 7.

Referring now to FIGURES l and 2 there is shown a stabilizer including a tubular body 10 having connection means at each end for connecting the stabilizer in a drill string, the connection means at the top being in the form of a threaded box 11 and that at the lower end being a threaded pin 12.

An annular member 13 is disposed around and welded at its inner periphery to the tubular body. The annular member includes an upper horizontal annular plate 14, a lower horizontal annular plate 15, and a plurality of azimuthally spaced apart vertical radial webs 16, welded to the plates.

Around the outer periphery of annular member 13 at azimuthally spaced apart locations, corresponding preferably to the positions of webs 16, are a lurality of support means for rolling, wall-contacting means, each support means including an upper bracket 20 and a lower bracket 21. Readily attachable and detachable means for con-. meeting the support means to the annular member each comprises a vertical tangential mounting plate 25 welded to the outer periphery of the annular member perpendicular to a web 16 and a similar mounting plate 26 welded to brackets 20, 21. The plates 20, 21 may be connected together in any readily attachable and detachable way, such as by means of welds, or, as shown, by means of bolts 27 and nuts 23. Each pair of brackets 20, 21 may be braced relative to the corresponding mounting plate 26 by a plurality of gussets 29.

Referring now to FIGURES 3 and 4, there is shown how an extension member 30 can be inserted in the means for connecting the annular member to the support means (brackets 20, 21), for the rolling, wall-contacting means. Extension member 39 includes a vertical, radial plate 31 and a plurality of horizontal gussets 32 welded thereto, with readily attachable and detachable means in the form of vertical, tangential plates 33, 34 at the inner and outer ends of plate 31, adapted for connection to the corresponding plates 25, 26, of the connecting means provided on the annular member 13 and the support means (brackets 20, 21) for the rolling, wall-contacting means. The plates 31, 32, 33, 34 are all welded together to form the extension member 30. The plates 25 and 26 are connected to plates 33, 34 in the same manner as plates 25 and 26, were connected together in FIGURES l and 2, e.g. by bolts 27 and nuts 28.

Referring now to FIGURES 5 and 6 the rolling, wallcontacting means comprises a roller 40 rotatably mounted on an axle 41, there being a slight clearance of the order of g inch between the outside of the axle and the inside of the roller. The roller is preferably made of an elastomer such as a rubber compound having a hardness as measured on the A scale of a Shore Durometer lying in the range of 35 to 90. The rubber may be reinforced with a tubular steel core 42. To assist in rubber flow during molding, the core may have a plurality of ports 43 extending therethrough from the inside to the outside of the core. The bearing surface at the inner periphery of roller 40 is preferably provided with a plurality of longitudinal flutes 44. The outer periphery of the roller is preferably a smooth cylindrical surface and the upper and lower ends of the roller are preferably bevelled at 45, 46.

The roller 40 is releasably mounted on axle 41 by the following means. Axle 41 is tubular. The lower end of axle 41 is received in an annular groove 50 in the top of disc 51 and the upper end of axle 41 is received in an annular groove 52 in the bottom of disc 53. Means is provided to keep axle 41 from turning in the annular grooves 50, 52, for example it is welded to one of the discs, e.g. disc 51. The lower side of disc 51 has a slot 55 therein to receive the top edge of bracket 21. The top side of disc 53 has a slot 56 therein to receive the lower edge of bracket 20. Disc 51 has a hole 58 therein in register with socket 59 in bracket 21. Disc 53 has a hole 60 therein in register with a bore 61 in bracket 20. A main pin 62 passing through bore 61, hole 60, axle 41, hole 58, and into socket 59 retains discs 51, 53 in position on brackets 20, 21. Drive fit, cross pins 63, 64 through brackets 20-, 21 and the upper and lower ends of main pin 62 retains pin 62 in position. A bore 65 in bracket 21 communicates with socket 59 to enable pin 62 to be driven and when it is desired to remove the discs 51, 53 from the brackets 20, 21 to replace roller 40 on axle 41, after first driving out cross pins 63, 64.

Referring now to FIGURES 7 and 8 there is shown a stabilizer the same as that described previously with reference to FIGURES 1 through 6- except for the construction of the tubular body and its drill string connections and the annular member around the tubular body. The stabilizer shown in FIGURES 7 and 8 is intended for use with flanged drill collars shown at 70, 71, which may be of the hollow double walled lead filled type, each provided with upper and lower connection flanges as at 72, 73. The tubular body, drill string connection means, and annular member of the stabilizer are provided in the form of a steel casting having a tube portion 75 with upper and lower connection flanges 76, 77 and a plurality of radial webs 77a. Welded to the outer peripheries of the flanges 76, 77 are a plurality of spokes each comprising upper and lower horizontal plates 78, 79 and vertical side plates 80. The side plates do not extend radially inward enough to contact the flanges 76, 77, leaving enough room for wrenches to be inserted, whereby the stabilizer flanges 76, 77 can be connected to the drill collar flanges 72, 73, by means of nuts 81 and bolts 82 passing through registering holes 83 in the flanges.

At the outer periphery of each spoke is provided a Vertical, tangential, plate 85 similar to plates 25 of the previously described embodiment of the invention. To plate 85 is bolted a plate 26 the same as in the previously described embodiment carrying brackets 20, 21 supporting the rolling, wall-contacting means.

Considering the spokes 78-80, and the flanges 76, 77, and the webs 77a to form an annular member disposed around tubular body 75, with the holes 88 providing means for connecting the tubular body to a drill string it is seen that the embodiment of the invention shown in FIGURES 7 and 8 is quite similar to that shown in FIGURES 1-6. Also, each embodiment may be viewed as including a tubular body with spoke means annularly disposed therearound comprising in FIGURES 7-8 the spokes 78-80 (and the webs 76), and in FIGURES 1-2 the webs 16 (with adjacent portions of plates 14, 15). Whether considered as an annular means or as spoke means annularly disposed around the tubular body, such means constitutes projecting means permanently aflixed to the body and extending radially therefrom to dispose the axes of the rolling, wall-contacting means at a distance from the exterior of the tubular'body that forms the fluid conduit and drive connection between the parts of the drill .string.

While preferred embodiments of the invention have been shown and described, modifications thereof can be made without departing from the scope of the invention.

That being claimed is:

1. A drill string stabilizer comprising a body having a flow passage extending vertically therethrough,

means for connecting the body in a drill string,

a plurality of rolling, wall-contacting means each including an axle and a roller rotatably disposed on the axle,

bracket means for supporting each wall-contacting means,

means connecting said bracket means to said body at azimuthally spaced apart positions around the body,

and means releasably mounting each axle on its bracket means, each said mounting means including upper and lower discs disposed at the ends of the axle, one of said discs being fixed to the axle and the other releasably disposed in an opening therein, each of said discs having a slot in its face on the opposite side thereof from said axle, said slots receiving respectively the under side of the top part of the bracket means and the top side of the lower part of the bracket means, and

means releasably securing said discs to said bracket means.

2. Combination of claim 1 in which the axle is a tube and said means releasably securing said discs to said bracket means comprises a pin extending through the axle into openings in the upper and lower parts of said bracket means, one of said openings extending through the bracket means to permit insertion and withdrawal of the pin as desired.

3. A drill string stabilizer comprising a tubular body having an upper end and a lower end,

means at each end of said body for making connection with a drill string,

spoke means annularly disposed around the periphery of the body at azimuthally spaced apart positions, positions,

a fixed axle adjacent the end of each spoke,

an elastomer roller rotatably mounted on each axle,

each roller being a tube whose inner periphery forms a bearing surface rotatably engaging the axle,

said bearing surface of each roller being fluted,

the outer surface of each roller being smooth and generally cylindrical,

the elastomer of each roller being a rubber compound having a Shore Durometer A scale hardness in the range 'of 35-90, and

a tubular steel reinforcement embedded in each roller below the outer cylindrical surface thereof.

4. A drill string stabilizer comprising a body having an upper end and a lower end and having a flow'passage extending through said body between said ends,

flange means at each end of said body for connecting said body to a drill string with said flow passage in fluid transmitting relationship with the drill string,

each flange means extending radially from'said body and having a plurality of bolt holes extending vertically therethrough, 1

spoke means annularly disposed around the periphery of the body at azimuthally spaced apart positions and extending radially from said body beyond said flange means,

each spoke extending vertically from one of said flange means to the other and being provided with openings in its sides for access to bolts passing through said bolt holes, and

5 6 a roller mounted at the end of each spoke for ro- 2,669,441 2/1954 Castonoli 175-323 X tation about an axis parallel to said flow passage. 3,103,391 9/1963 Leathers 3084 References Cited by the Examiner FOREIGN PATENTS UNITED STATES PATENTS 5 38,180 12/1935 Holland.

712,486 11/1902 Black 308-6 79 22 2/190 Kams 30 4 MARTIN P. SCHWADRON, Primary Examiner. 892,849 7/1908 Karns 175-325 X 1,905,158 4/1930 Graig 308 6 DAVID J. WILLIAMOWSKY, Examiner.

1,923,328 8/1933 Reed 308-6 10 L. L. JOHNSON, Assistant Examiner. 

1. A DRILL STRING STABILIZER COMPRISING A BODY HAVING A FLOW PASSAGE EXTENDING VERTICALLY THERETHROUGH, MEANS FOR CONNECTING THE BODY IN A DRILL STRING, A PLURALITY OF ROLLING, WALL-CONTACTING MEANS EACH INCLUDING AN AXLE AND A ROLLER ROTATABLY DISPOSED ON THE AXLE, BRACKET MEANS FOR SUPPORTING EACH WALL-CONTACTING MEANS, MEANS CONNECTING SAID BRACKET MEANS TO SAID BODY AT AZIMUTHALLY SPACED APART POSITIONS AROUND THE BODY, AND MEANS RELEASABLY MOUNTING EACH AXLE ON ITS BRACKET MEANS, EACH SAID MOUNTING MEANS INCLUDING UPPER AND LOWER DISCS DISPOSED AT THE ENDS OF THE AXLE, ONE OF SAID DISCS BEING FIXED TO THE AXLE AND THE OTHER RELEASABLY DISPOSED IN AN OPENING THEREIN, EACH OF SAID DISCS HAVING A SLOT IN ITS FACE ON THE OPPOSITE SIDE THEREOF FROM SAID AXLE, SAID SLOTS RECEIVING RESPECTIVELY THE UNDER SIDE OF THE TOP PART OF THE BRACKET MEANS AND THE TOP SIDE OF THE LOWER PART OF THE BRACKET MEANS, AND MEANS RELEASABLY SECURING SAID DISCS TO SAID BRACKET MEANS. 